The invention relates to a method and an apparatus especially advantageous for horizontal continuous casting of liquid metals, particularly steel, in which the casting metal, flowing in a cooled horizontal continuous casting cast-iron mold, is under the influence of gravitational forces of the liquid metal contained in the storage container and, furthermore, is subject to electro-magnetically produced forces. The electro-magnetically produced forces affect the casting metal in the direction of the metal strand casting.
The present invention, by utilizing horizontal continuous casting in contrast to the prior art vertical, vertical with a bending mechanism or semi-horizontal continuous casting makes unnecessary both bending of the cooling metal strand casting from the normal vertical axis into the horizontal axis, as well as the expenditure of high finances, incident to high building structures normally associated with vertical continuous casting. The fully horizontal casting apparatus and process of the present invention eliminate all bending forces normally incident to vertical continuous casting processes having deflection means after casting.
A fully horizontal continuous casting method and apparatus, as compared to the greater capital expenditure inherent in erecting a structure for a vertically arranged continuous casting apparatus, nevertheless has heretofore encountered certain technical difficulties which originate, in particular, from the horizontal position of the casting strand during the cooling period of the casting metal. More specifically, the prior art horizontal casting apparatus and methods do not fully eliminate the possibility that the hollow space, a result of the pulling off and solidification of the casting metal strand, will not be refilled with liquid metal. Additionally, conventional horizontal continuous castings methods and apparatus cannot insure, in contrast to vertical continuous casting methods and apparatus, that the hollow space formed as the liquid metal first leaves the water-cooled mold, will be continuously shifted into the upper cross sectional area of the casting strand and continuously filled. The hollow spaces, if they are not filled in, are subject to a certain asymmetry in separating and settling operations and result in metal products containing inherent failure possibilities.
The conventional apparatus for horizontal strand casting evince several other disadvantages. For example, conventional horizontal continuous casting apparati work on the principle of pulling out the liquid metal strand such that the liquid casting metal is continuously replenished in the horizontal continuous casting cast-iron mold from the storage container. In such apparati the mechanical connection or conduit between the storage container and the horizontal continuous casting cast-iron mold is always a critical element. Depending upon the specific alloy elements of the liquid casting metal and other factors, the casting temperature of the liquid metal may be above 1500.degree. C. The occurrence of such relative high temperatures in connection with continuously used apparatus elements, such as, for example, the storage container, the conduit or drain pipe, the horizontal continuous casting cast-iron mold, necessarily means that the elements must be easily accessible for potentially frequent repair work. The mechanical elements of the conventional horizontal continuous casting installations are difficult to repair and/or modify. The present invention is extremely simple to repair and/or modify. On the other hand, metallurgical requirements do not permit the total simplification of the apparatus elements to such an extent that, for example, the casting metal is simply guided from the storage container into the continuous casting cast-iron mold through troughs open at the top. A degree of complexity of apparatus elements is necessarily inherent in continuous casting of metallurgical products under tightly controlled conditions. The present invention, more fully explained hereinafter, accomplishes both of the just mentioned goals in a mutually consistent manner, i.e., it is easy to repair and the transfer of liquid metal from storage container to mold is not open to the atmosphere. A precisely adjustable set of interconnected apparatus elements are provided for continuous horizontal casting of metallurgical products which elements, however, can be quickly and simply repaired or replaced, as required.
In German reference DE-AS No. 1,296,747 the suggestion is made to provide a horizontal supply line or conduit between a liquid metal storage container, from which the supply of liquid metal originates, and the horizontal continuous casting cast-iron mold; the conduit being provided, around its periphery, with a magnetic pump. The desired purpose of the magnetic pump is to maintain a steady pressure of the liquid metal in the horizontal continuous casting cast-iron mold. The steady pressure of liquid metal in the casting mold produces a high filling content of liquid metal in the interior of the horizontal continuous casting cast-iron mold, thereby tending to reduce the existence of internal voids in the finished metal product. Additionally, the pressure of the liquid metal in the horizontal continuous casting cast-iron mold, by being maintained, allows the heat exchange between the liquid casting metal and the interior walls of the horizontal continuous casting cast-iron mold to be regulated, thereby enhancing simplified and more uniform solidification.
The conventional method of continuous casting of liquid metal operates mostly in air-tight conditions so that the negative effects of reoxidation of the liquid casting metal is eliminated or reduced. The apparatus disclosed in the above identified German reference, by providing a horizontal supply conduit between the horizontal continuous casting cast-iron mold and the storage container, the conduit being manufactured of heat-resistant material, results in a relative high heat loss and an unfavorably long travel distance for the liquid metal. The apparatus disclosed therein is relatively difficult to adjust while in operation and is susceptible to breakdown and other problems.